1. Field of the Invention
The present invention relates to an automatic processing apparatus for processing, with processing solutions, a photosensitive material inserted through an insertion slot after imagewise exposure.
2. Description of the Related Art
In case that a printing plate for printing high-volume printed matter is produced, proofing to check that there are no mistakes in lettering in the printing plate is performed. Further, when color printing is performed, proofing that includes checking that there are no errors in colors is performed. Therefore, for example, when color printing is performed, a color proof image is formed on a photosensitive material.
In order to produce such a color proof, a color proof producing device is used. In the color proof producing device, an image exposure device, which exposes the photographic material, is used as an output device, and an automatic processing apparatus (hereinafter referred to as a "processor"), which develops and processes the photographic material exposed in the output device, is connected to the output device.
Generally, in the processor, a photosensitive material that has been inserted through the insertion slot is immersed in processing solutions, for example, a developing solution, a bleach-fixing solution, a rinsing solution (or a washing water) to perform processing with processing solutions. Then, a drying is performed. At this time, the processing solutions e. g. the developing solution, the bleach-fixing solution, etc. are temperature-controlled so as to optimally finish the photosensitive material.
In such a processor, the processing solutions are stored within the apparatus and are temperature-controlled. Therefore, as the air temperature increases, the humidity in the processor increases. Further, corrosive gases from constituents of the processing solutions are retained within the apparatus.
Therefore, if air in the processor enters the output device which is connected to the processor, the air may be condensed in the output device, and the condensed moisture and the corrosive gases may cause corrosion of internal components (parts) of the output device.
When making a printing plate for printing, a plate-making method wherein image data is transformed to digital signals and a printing plate is exposed to a light beam modulated on the basis of this image data is widely used. In this plate-making method, a color proof producing device, in which a processor is connected to an image exposure device to which the photosensitive material for proofing is exposed on the basis of image data, is used.
For example, in the image exposure device to which the photosensitive material is exposed on the basis of the image data, the photosensitive material is wound around a rotating drum, and the rotating drum is rotated at high speed while holding the photosensitive material by suction due to negative pressure. Thus, the photosensitive material is imagewise scan-exposed.
In the image exposure device which holds photosensitive material by suction with negative pressure, when the photosensitive material is fitted to the rotating drum and held, pressure in the device may become lower than pressure outside the device. In case that a processor is connected to such image exposure device, and that the photosensitive material is fed from the image exposure device into the insertion slot of the processor, when internal pressure of the image exposure device becomes low, air in the processor will be sucked into the image exposure device through the insertion slot, which will be condensed and make the components in the image exposure device to corrode.
Therefore, there are color proof producing devices provided with an opening and closing mechanism such as a shutter in the insertion slot of the processor. The insertion slot is opened when the photosensitive material is passed through. The insertion slot is closed when the photosensitive material is not passed through, to prevent air in the processor from flowing into the image exposure device.
Further, there are color proof producing devices provided with an exhaust fan in the processor. Air in the processor is exhausted by this exhaust fan. Thus, inflow of air from the processor through the insertion slot into the image exposure device is prevented.
However, in order to prevent air in the processor from flowing into the image exposure device by an exhaust fan when pressure in the image exposure device is lowered, it is necessary to use a high capacity exhaust fan and it is difficult to reliably prevent outflow of air from the insertion slot.
Further, even though the exhaust fan is provided to exhaust air from the processor, air in the processor flows through the insertion slot into the image exposure device, where the interior of the image exposure device has a negative pressure. That is, in a rapid processing, when discharge of photosensitive material on which an image has been printed and attachment of subsequent photosensitive material onto the rotating drum by suction are simultaneously performed, and the insertion slot of the processing section of the processor is opened under the reduced internal pressure of the image exposure device, air in the processor flows into the image exposure device.
Therefore, to prevent air from flowing through the insertion slot of the processing section of the processor into the image exposure device, it is necessary to extend processing intervals of the photosensitive materials, and as a result, processing efficiency is reduced.